examples/Base/BufsAndStrings/DynamicBuffers/DynamicBuffers.cpp

/*
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  list of conditions and the following disclaimer.
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  this list of conditions and the following disclaimer in the documentation
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  may be used to endorse or promote products derived from this software
  without specific prior written permission.

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AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

Description:  
*/


#include "CommonFramework.h"

//
// Common literal text
//
_LIT(KTxtNewLine,"\n");

LOCAL_C void writeBuf(CBufBase* aBuf);
LOCAL_C void standardBufferStuffL(CBufBase* aBuf);
LOCAL_C void showExpandL();
LOCAL_C void waitForKey();
//
// do the example
//
LOCAL_C void doExampleL()
    {
        //
        // do flat buffer demonstration
        //
        _LIT(KTxtFlatBufDemo,"Flat buffer demonstration\n");
        console->Printf(KTxtFlatBufDemo);
        CBufFlat* flatBuf=CBufFlat::NewL(4);
        CleanupStack::PushL(flatBuf);
        flatBuf->SetReserveL(32);
        _LIT(KTxtFlatBufCapacity,"flat buffer capacity=%d\n");
        console->Printf(KTxtFlatBufCapacity,flatBuf->Capacity());
        standardBufferStuffL(flatBuf);
        CleanupStack::PopAndDestroy();
        waitForKey();
        //
        // do segmented buffer demonstration
        //
        _LIT(KTxtSegBufDemo,"Segmented buffer demonstration\n");
        console->Printf(KTxtSegBufDemo);
        CBufSeg* segBuf=CBufSeg::NewL(4);
        CleanupStack::PushL(segBuf);
        standardBufferStuffL(segBuf);
        CleanupStack::PopAndDestroy();
        waitForKey();
        //
        // show ExpandL() and ResizeL()
        //
        showExpandL();
        }


LOCAL_C void standardBufferStuffL(CBufBase* aBuf)
        {
        //
        // insert text into buffer (6 chars)
        //
        _LIT(KTxtHello,"Hello!");
        aBuf->InsertL(0,(TAny*)(&KTxtHello)->Ptr(),(&KTxtHello)->Size());
        writeBuf(aBuf);
        //
        // append more text into buffer (another 6 chars)
        //
        //
        _LIT(KTxtWorld," world");
        aBuf->InsertL(10,(TAny*)(&KTxtWorld)->Ptr(),(&KTxtWorld)->Size());
        writeBuf(aBuf);
        //
        // read the 5 characters starting at character
        // position 3 from the buffer into a descriptor.
        //
        //
        TBuf<5> des;
        aBuf->Read(6,(TAny*)des.Ptr(),des.Size());
        _LIT(KTxtRead,"read: %S\n");
        console->Printf(KTxtRead,&des);
        //
        // [over]write 5 characters at character position 6
        //
        //
        _LIT(KTxtFolks,"folks");
        aBuf->Write(12,(TAny*)(&KTxtFolks)->Ptr(),(&KTxtFolks)->Size());
        writeBuf(aBuf);
        //
        // delete characters
        //
        TInt startpos = 5;
        TInt length   = 6;
        startpos <<= 1;
        length   <<= 1;
        aBuf->Delete(startpos,length);
        writeBuf(aBuf);
        //
        // compress
        //
        aBuf->Compress();
        writeBuf(aBuf);
        }

LOCAL_C void writeBuf(CBufBase* aBuf)
        {
        //
        // print, segment by segment
        //
        _LIT(KTxtBuffer,"buffer:");
        console->Printf(KTxtBuffer);
        TInt  bufpos=0;
        TPtrC8 bufptr=aBuf->Ptr(bufpos);
        while (bufptr.Length()>0)
                {
                //
                // write out this segment of the buffer.
                // Note that the descriptor 'display' is built differently
                // for Unicode; it also assumes an even number of bytes;
                // this is valid because the granularity of the buffer is 4.
                //
                TPtrC display;
                display.Set((TUint16*)bufptr.Ptr(),(bufptr.Length()>>1));
                _LIT(KFormat1," [%d,%d] %S");
                console->Printf(KFormat1, bufpos, bufptr.Length(), &display);
                //
                // update position within the buffer
                // and the pointer-descriptor.
                //
                bufpos+=bufptr.Length();       // update position
                bufptr.Set(aBuf->Ptr(bufpos)); // should be the next segment
                }
        console->Printf(KTxtNewLine);
        }

        

LOCAL_C void showExpandL()
        {
        _LIT(KTxtShowExpand,"Showing ExpandL()\n");
        console->Printf(KTxtShowExpand);
        //
        // allocate the segmented buffer with 
        // a granularity of 4
        //
        CBufBase* buf=CBufSeg::NewL(4);
        CleanupStack::PushL(buf);
        //
        // insert text into buffer (12 UNICODE chars)
        //
        _LIT(KTxtHelloWorld,"Hello world!");
        buf->InsertL(0,(TAny*)(&KTxtHelloWorld)->Ptr(),(&KTxtHelloWorld)->Size());
        //
        // reserve space for (or 16 16-bit chars (32 bytes))
        //
        buf->ExpandL(12,32); // expand by 32 - may fail
        _LIT(KTxtBufExpanded,"Buffer expanded with uninitialized space: ");
        console->Printf(KTxtBufExpanded);
        writeBuf(buf);
        //
        // now insert 16 16-bit characters
        // one at time.
        //
        // This is CLEARLY INEFFICIENT but shows
        // how successive calls to Write() can be done
        // without risk of failing for lack of memory.
        //
        _LIT(KTxtAtoP,"abcdefghijklmnop");
        TBufC<16> source(KTxtAtoP);
        for (TInt i=0; i<16; i++)
                {
                buf->Write((i+6)<<1,(TAny*)&source[i],2);
                }
        _LIT(KTxtExpandedFilled,"expanded space filled: ");
        console->Printf(KTxtExpandedFilled);
        writeBuf(buf);
        //
        // now adjust size down to 18
        //
        buf->ResizeL(18);
        _LIT(KTxtResized,"resized:");
        console->Printf(KTxtResized);
        writeBuf(buf);
        //
        // destroy buffer
        //
        CleanupStack::PopAndDestroy();
        }

LOCAL_C void waitForKey()
        {
        _LIT(KTxtPressAnyKey,"[press any key]");
        console->Printf(KTxtPressAnyKey);
        console->Getch();
        console->Printf(KTxtNewLine);
        }

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